CVE-2026-52933

Summary

In the Linux kernel, the following vulnerability has been resolved:

io_uring/poll: fix signed comparison in io_poll_get_ownership()

io_poll_get_ownership() uses a signed comparison to check whether poll_refs has reached the threshold for the slowpath:

if (unlikely(atomic_read(&req->poll_refs) >= IO_POLL_REF_BIAS))

atomic_read() returns int (signed). When IO_POLL_CANCEL_FLAG (BIT(31)) is set in poll_refs, the value becomes negative in signed arithmetic, so the >= 128 comparison always evaluates to false and the slowpath is never taken.

Fix this by casting the atomic_read() result to unsigned int before the comparison, so that the cancel flag is treated as a large positive value and correctly triggers the slowpath.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxa26a35e9019fd70bf3cf647dcfdae87abc7bacea < 81bf96b0abbfa4cd47ea32e12596aed3855fb2f3affected
LinuxLinuxa26a35e9019fd70bf3cf647dcfdae87abc7bacea < cf522703d4f194991615763697ae25a3f9539763affected
LinuxLinuxa26a35e9019fd70bf3cf647dcfdae87abc7bacea < fc47043f3d9af3efa407665b47f8378ec691ba18affected
LinuxLinuxa26a35e9019fd70bf3cf647dcfdae87abc7bacea < ea0697129807d718037f618221037aa0660ee3c5affected
LinuxLinuxa26a35e9019fd70bf3cf647dcfdae87abc7bacea < c6d191164dc81838d8dbf452a6000f68c558d1aeaffected
LinuxLinuxa26a35e9019fd70bf3cf647dcfdae87abc7bacea < 326941b22806cbf2df1fbfe902b7908b368cce42affected
LinuxLinux4b702b7d11ce1b9d26fc6d7c5a7ef4ac1d455048affected
LinuxLinuxbc4e6ee16778149811333a969a7a893d4cc110c5affected
LinuxLinux5.15.82 < 5.16affected
LinuxLinux6.0.11 < 6.1affected
LinuxLinux6.1affected
LinuxLinux0 < 6.1unaffected
LinuxLinux6.1.175 <= 6.1.*unaffected
LinuxLinux6.6.140 <= 6.6.*unaffected
LinuxLinux6.12.86 <= 6.12.*unaffected
LinuxLinux6.18.27 <= 6.18.*unaffected
LinuxLinux7.0.4 <= 7.0.*unaffected
LinuxLinux7.1 <= *unaffected

Weaknesses

References